Ella Pallister was a student at Thomas Hardye School in Dorchester.
In a statement the school said: "We are devastated by the news of the tragic and sudden death of Ella Pallister.
"She was studying in Year 13 and she was a popular, bubbly, hard- working and caring student.
"Her closest friends are in shock, but the whole sixth form and school community are grieving for her loss.
"Our thoughts and condolences are with her family at this very sad time."
More top news
Thursday's weather for the west of the region
Thursday's weather for the east of the region
Foreign Office Minister Tobias Ellwood has been praised after attempting to save the life of the police officer killed in New Palace Yard.